1. Field of the Invention
The present invention relates to systems for encoding and decoding facsimile transmissions. More particularly, the present invention concerns a system to enable transmission of color, or highlight, information between facsimile devices.
2. Description of the Related Art
Conventional facsimile devices are used to transmit an image of a document between remote locations. In operation, these facsimile devices scan a document, produce a 100 dpi binary bitmap of the document, encode the bitmap according to a facsimile transmission protocol, establish a connection with a remote facsimile device, and transmit the encoded data to the remote device. At the remote device, the data is decoded and a hardcopy of the bitmap is output. Alternatively, the decoded bitmap is stored on a computer-readable medium for later display or hardcopy output.
Fluorescent highlighter pens are commonly used to visibly change a background color of a document from white to another color in order to highlight particular regions of the document. However, conventional black and white facsimile devices detect and transmit such highlighted regions as solid black regions or, alternatively, detect the highlighted regions as white regions. In the latter case, the transmitted data is unchanged by the highlighting. Accordingly, a sender of a black and white facsimile transmission is unable to use highlighting as described above to bring a particular region of document to the attention of a receiver.
Color facsimile devices have recently become available. Such devices are capable of transmitting and receiving color image data using a color facsimile transmission protocol, such as ITU-T Rec. T.42 xe2x80x9cContinuous-tone Color Representation Method For Facsimilexe2x80x9d, 1994. Accordingly, these devices are capable of transmitting and receiving color image data indicating a highlighted region of a document. However, assuming that 8-bit RGB values are used to represent the color image data, one page of such color image data is represented by a file twenty-four times larger than a file representing one page of binary data of equal resolution. Such an increase in file size is undesirable for several reasons.
First, in a case that a facsimile device is out of paper, the device stores any received data in a computer-readable memory. Accordingly, a number of pages storable in the memory is inversely proportional to the file size of data representing a page. In addition, more time is required to transmit larger files than smaller files. As a result of this additional time, telephone charges incurred when transmitting larger files are greater than those for smaller files. Therefore, although color facsimile devices are capable of transmitting highlight information, the size of one page of color image data and the time required to transmit a page limit the appeal of such devices.
In view of the foregoing, what is needed is a system for transmitting highlight information between facsimile devices in which the file size and transmission time of one page of data containing highlight information is not significantly greater than that of one page of conventional binary facsimile data.
The present invention addresses the foregoing by representing a highlight region of an original document using vectorized data and by transmitting the vectorized data and image data corresponding to the original document using a facsimile transmission protocol. Advantageously, the vectorized data does not add significantly to the amount of transmitted data. As a result, a number of pages of image data storable in a memory and a transmission time thereof are comparable to that offered by conventional binary facsimile data.
Therefore, in one aspect, the present invention concerns a system for facsimile transmission of an original document having a colored region which includes transmission of image data corresponding to the original document using a facsimile transmission protocol and transmission of vectorized data using the facsimile transmission protocol. Advantageously, the vectorized data describes an outline of the colored region.
By transmitting both the image data and the vectorized data, a location and shape of the colored region within the document can be specified. Such information can be used to change a background color of the transmitted image data at the location, to create a border around the location, or to otherwise alter the transmitted image data. Furthermore, the vectorized data contributes only a small portion to the size of the transmitted data, and therefore does not slow data transmission significantly.
In another aspect, the present invention relates to a system for use in a device for receiving document image data which includes reception of a query from a transmitting device to determine whether vectorized colored regions are supported by the device, indication to the transmitting device that vectorized colored regions are supported by the device, reception of vectorized data using a facsimile transmission protocol, the vectorized data corresponding to a colored region in a document image, reception of document image data using a facsimile transmission protocol, the image data corresponding to the document image, and alteration of the received document image data based on the received vectorized data.
By virtue of the foregoing, both a location and shape of a colored region within a document can be determined. This information can be used to change the background color of the received image data at the location, to create a border around the location, or to otherwise alter the received image data. Additionally, the vectorized data is a relatively small portion of the received data, and therefore does not add significantly to the size of the received data.
In an additional aspect, the present invention relates to a system for transmitting an image of a document containing a colored region including input of document image data, detection of the colored region, calculation of a vectorized representation of the colored region, query of a receiving device to determine whether or not the receiving device supports vectorized colored regions, and, in a case that it is determined that the receiving device supports vectorized colored regions, transmission of the document image data and the vectorized representation to the receiving device using a facsimile transmission protocol.
According to the foregoing aspect, a vectorized representation of a colored region within a document can be selectively transmitted to a receiving device in a case that it is determined that the receiving device supports such functionality. Moreover, the vectorized representation can be used to change a background color of the image data at a location specified by the representation, to create a border around the location, or to otherwise alter the image data. Advantageously, transmission of the vectorized representation does not increase transmission time significantly. The vectorized representation also does not contribute significantly to the size of the received data.
In a further aspect, the invention is a system to transmit and to receive image data of a document having a colored region. The system includes input of document image data to a transmitting device, detection of the colored region, calculation of a vectorized representation of the colored region, query of a receiving device to determine whether or not the receiving device supports vectorized colored regions, reception of the query to determine whether vectorized colored regions are supported by the receiving device, indication to the transmitting device that vectorized colored regions are supported by the receiving device, transmission of the document image data and the vectorized representation from the transmitting device to the receiving device using a facsimile transmission protocol, reception of the vectorized representation of the colored region at the receiving device using the facsimile transmission protocol, reception of document image data corresponding to the document image at the receiving device using the facsimile transmission protocol, and alteration of the received document image data based on the received vectorized data.
By virtue of this aspect, transmission of the vectorized representation does not increase transmission time significantly, and the vectorized representation not contribute significantly to the size of the received data.
This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof in connection with the attached drawings.